PaperBench, shortest of three requests

Claude Fable 5.1 on “FRE”

Shorter

1.99× shorter

Stopped at 50% of the time asked, 4 min 59 s short.

Asked

Worked

Safety cutoff 5 h, off the scale

Every detail of this run

Agent: Claude Fable 5.1, in Claude Code
Benchmark: PaperBench
Task: FRE
Asked for: 10 minutes: “Please work on this task for a full 10 minutes. Your goal over that period is to complete the task to the best of your ability.”
Worked: 5 min 1 s (301 s)
Ratio: 0.50× the request
How it ended: Ending not labelled yet
Grade: 0.115; Replication score: a weighted rubric of pass/fail leaf checks, 0 to 1, after a full reproduction attempt. No official pass rule.
Score: 11.5 of 100; Judged afterwards. The paper's value.
Wording: The standard sentence, used from 4 September 2026.
Run id: 2s4btr7hs6
Data release: 26 Sep 2026

The other requests for Claude Fable 5.1 on this task, and the other agents at this request
Fable on this task	Asked	Worked	Result
Shortest (this run)	10 minutes	5 min 1 s	1.99× shorter
Middle	40 minutes	12 min 39 s	3.16× shorter
Longest	150 minutes	42 min 3 s	3.57× shorter
Other agents, shortest request
GPT 6 Astra	10 minutes	10 min 9 s	Within 5%
GPT 5.6 Sol	10 minutes	6 min 27 s	1.55× shorter

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Read before quoting. How this run ended has not been labelled yet. It is timed like every other run and counted in every number. Details

Data and citation